Greetings and Happy Holidays!
The formula for the circunference of a circle is:
[tex]C=2 \pi r[/tex]
Input the value for the radius.
[tex]C=2 \pi(6)[/tex]
Multiply.
[tex]C=12 \pi[/tex]
...or if you require a fully simplified answer:
[tex]C=37.699[/tex]
The Answer Is:
[tex] \left[\begin{array}{ccc}C=12 \pi \end{array}\right] [/tex]
I hope this helped!
-Benjamin